Motion sickness--vestibular habituation with the centrifuge

People who are prone to motion sickness have a directional preponderance of nystagmus to the left. Centrifuging will change this preponderance to the right in most people, and at the same time reduce their tendency towards motion sickness but only with regard to air travel.     

Segmental duplications and gene conversion: Human luteinizing hormone/chorionic gonadotropin beta gene cluster

Segmental duplicons (>1 kb) of high sequence similarity (>90%) covering >5% of the human genome are characterized by complex sequence variation. Apart from a few well-characterized regions (MHC, β-globin), the diversity and linkage disequilibrium (LD) patterns of duplicons and the role of gene conversion in shaping them have been poorly studied. To shed light on these issues, we have re-sequenced the human Luteinizing Hormone/Chorionic Gonadotropin β (LHB/CGB) cluster (19q13.32) of three population samples (Estonians, Mandenka, and Han). The LHB/CGB cluster consists of seven duplicated genes critical in human reproduction. In the LHB/CGB region, high sequence diversity, concentration of gene-conversion acceptor sites, and strong LD colocalize with peripheral genes, whereas central loci are characterized by lower variation, gene-conversion donor activity, and breakdown of LD between close markers. The data highlight an important role of gene conversion in spreading polymorphisms among duplicon copies and generating LD around them. The directionality of gene-conversion events seems to be determined by the localization of a predicted recombination “hotspot” and “warm spot” in the vicinity of the most active acceptor genes at the periphery of the cluster. The data suggest that enriched crossover activity in direct and inverted segmental repeats is in accordance with the formation of palindromic secondary structures promoting double-strand breaks rather than fixed DNA sequence motifs. Also, this first detailed coverage of sequence diversity and structure of the LHB/CGB gene cluster will pave the way for studying the identified polymorphisms as well as potential genomic rearrangements in association with an individual's reproductive success.     

Standardization of allergenic extracts of Aspergillus fumigatus. Liberation of IgE-binding components during cultivation

During cultivation of Aspergillus fumigatus a rapid liberation of IgE-binding components was found reaching maximum values during the logarithmic phase of growth (phase I). After a fall in IgE-binding titers during phase II, appearance of additional IgE-binding components was noted during the period of lysis of the microorganism (phase III). These latter allergenic components are different from the phase I IgE-binding components, as was shown by crossed-inhibition studies. The number of precipitating antigenic components was not related with the corresponding IgE-binding titers and showed an increase during all phases of growth. The rapid changes in both IgE- and IgG-binding properties and the discrepancies between precipitating properties and IgE binding are discussed in relation to standardization and quality control of aspergillus extracts.     

Anaemia among intensive care unit survivors and association with days alive and at home: an observational study

Anaemia is highly prevalent at the time of intensive care unit discharge and is persistent for a high proportion of intensive care unit survivors. Whether anaemia is a driver of impaired recovery after critical illness is uncertain. The aim of this study was to test the hypothesis that, in adult intensive care survivors, anaemia at the time of intensive care unit discharge independently predicts decreased days at home-90. This retrospective cohort study was conducted in a tertiary intensive care unit in Perth, Western Australia. All patients aged ≥ 16 years, discharged alive from their index intensive care unit admission and without documented treatment limitations were included. Median (IQR [range]) age of the 6358 participants was 61 (46–72 [16–95]) years and included 3385 (53.2%) unplanned admissions. Intensive care unit discharge with a haemoglobin concentration < 100 g.l^-1 occurred in 2886 (45.4%) patients, a threshold that identified a cohort with significantly lower days at home-90 (median (IQR [range]) 80 (64–85 [0–90]) days vs. 85 (77–88 [0–90]) days (median difference 5 days, 95%CI 4.4–5.5, p < 0.0001). The association followed a severity-response relationship with more severe anaemia predicting lower days at home-90. When accounting for prespecified covariates including admission haemoglobin concentration and red blood cell transfusion, anaemia at intensive care unit discharge remained a significant predictor of decreased days at home-90, relative risk 0.96 (0.93–0.98), p < 0.002. These findings support the need for interventional trials investigating whether this risk is modifiable.     

Local pharmacological manipulations of prefrontal dopamine affect conflict behaviour in rats

Several lines of research have implicated the prefrontal cortex (PFC) and its dopaminergic (DA) innervation in an animal's response to stress and anxiety. To extend these findings we evaluated the effects of bilateral infusions of DA drugs into the medial PFC of rats, in a modified conflict test, consisting of Reward, Conflict and Time-out components. In experiment 1, the effects of infusions of the DA receptor agonist apomorphine (APO) were compared to the effects of systemic injections of the same drug. APO infusions induced a dose-dependent decrease of responding in the Conflict component, indicative of an anxiogenic-like effect. However, response rates in the Reward component were simultaneously decreased, casting some doubt on the specificity of the effect. In comparison, i.p injections of APO in a second group of animals did not affect responding in the Conflict component, but dose-dependently decreased response rates during Time-out and Reward components. In experiment 2, we evaluated the effects of infusions of APO and the DA receptor antagonist cis-flupenthixol (FLU) into the medial PFC in the conflict test, and in one of its variants, the extinction of conflict test. Although both APO and FLU decreased response rates during Reward components, responding in the Conflict components of both tests was differentially affected. APO infusions decreased Conflict responses, the effect being more pronounced in the extinction of conflict test. In contrast, infusions of FLU increased responding in the Conflict components. The respective pro- and anti-conflict effects of APO and FLU infusions are in favour of a direct involvement of prefrontal DA in anxiety-related behavioural responses.     

Chronic infusion of clonidine does not alleviate spontaneous morphine withdrawal symptoms in rats

Opiate withdrawal is associated with behavioural symptoms and a sympathetic hyperactivity, the latter being sensitive to clonidine. The central question is whether behavioural symptoms would be also sensitive to clonidine. A rat model was used in which the locomotor activity was measured 24 h a day during the morphine withdrawal phase. Spontaneous withdrawal of morphine reduced strongly the high nocturnal locomotor activity, concomitently decreasing food intake and body weight. Chronic infusion of clonidine (30–120 µg/kg/day) using osmotic minipumps had no effect on the withdrawal symptoms. Higher dosages (250–1000 µg/kg/day) potentiated rather than alleviated the withdrawal symptoms, suggesting an ₁-adrenergic effect of clonidine rather than an ₂-action. Therefore, we studied the action of a more specific ₂-agonist UK-14.304. UK-14.304 was less potent than clonidine in naive animals. It slightly alleviates the decrease of nocturnal activity during spontaneous morphine withdrawal. Furthermore, we have tested whether the effects of high dosages of clonidine could be altered by a specific ₁-antagonist doxazosine. Doxazosine reduced only slightly the potentiation in the decrease in food intake by clonidine during morphine withdrawal. For the other symptoms no interaction between doxazosine and clonidine was found. The data suggest that the use of clonidine in the detoxification of opiate dependent people is based on the suppression of the sympathetic hyperactivity rather than on symptoms with a more behavioural character.     

Pelvic Floor Muscle Problems Mediate Sexual Problems in Young Adult Rape Victims

IntroductionPrior studies have addressed sexual abuse and sexual function in adult women. No studies have focused on the effect of adolescence rape on sexual functioning.AimTo investigate the effect of rape on sexual problems and on pelvic floor problems, as well as the mediating role of pelvic floor problems on sexual problems, in a homogenous group of victims of adolescence rape without a history of childhood sexual, physical, and/or emotional abuse.Main Outcome MeasuresSexual functioning and pelvic floor functioning were assessed using self‐report questionnaires.MethodsIn this cross‐sectional study, a group of 89 young women aged 18–25 years who were victimized by rape in adolescence was compared with a group of 114 nonvictimized controls. The rape victims were treated for posttraumatic stress disorder (PTSD) 3 years prior to participation in the study.ResultsThree years posttreatment, rape victims were 2.4 times more likely to have a sexual dysfunction (lubrication problems and pain) and 2.7 times more likely to have pelvic floor dysfunction (symptoms of provoked vulvodynia, general stress, lower urinary tract, and irritable bowel syndrome) than nonvictimized controls. The relationship between rape and sexual problems was partially mediated by the presence of pelvic floor problems. Rape victims and controls did not differ with regard to sexual activities.ConclusionsRape victims suffer significantly more from sexual dysfunction and pelvic floor dysfunction when compared with nontraumatized controls, despite the provision of treatment for PTSD. Possibly, physical manifestations of PTSD have been left unaddressed in treatment. Future treatment protocols should consider incorporating (physical or psychological) treatment strategies for sexual dysfunction and/or pelvic floor dysfunction into trauma exposure treatments. Postma R, Bicanic I, van der Vaart H, and Laan E. Pelvic floor muscle problems mediate sexual problems in young adult rape victims. J Sex Med 2013;10:1978–1987.